Police and fire crews were called to a suspected deliberate fire in Yeovil overnight.
Crews from the town as as well as Martock and Sherborne were called to Addlewell Lane just before 3am.
An ambulance crew were also called as a precaution to the derelict cottage.
The property owner was located at 4.45am.
A total of five fire engines attended the scene.
A spokesperson for Devon & Somerset Fire & rescue said: "A total of five fire appliances from Yeovil, Martock and Sherboren are attending this incident accompanied by several specialist supporting appliances and officers.
"Crews are currently set up and attempting to extinguish fire.
"Police are in attendance as this fire is believed to be a deliberate ignition, ambulance are also in attendance due to the possibility of possible persons reported."